DENVER (CBS4) – CBS4 has learned that the Colorado attorney general has joined other states to investigate Volkswagen due to allegations of consumer fraud. The automaker has admitted it rigged diesel cars to pass emissions tests that it billed as clean.

The VW diesels were supposed to be supercars, a Volkswagen diesel that got great gas mileage and ran cleanly. But one Jetta diesel owner, Chris Page, was stunned after learning VW was cheating on its emissions tests.

“I was a little disappointed in the company because I enjoyed the car,” he said.

Scientists from CSU perform an emissions test on a VW Jetta (credit: CBS)

CBS4 asked the experts who study engines at Colorado State University’s “Powerhouse” to help out. They hooked up the car to a $100,000 device that can detect nitrogen oxides and other pollutants. We then went for a ride.

CBS4’s Rick Sallinger takes a Jetta for a cruise with scientists from CSU (credit: CBS)

Shantanu Jathar, monitoring the device, told us, “What is happening here is we are in a real world environment with real stoplights, real highways real arterial worlds.”

Scientists from CSU perform an emissions test on a VW Jetta (credit: CBS)

We drove for about half an hour in the country and in the city, then we looked at the results displayed on the computer. Most EPA pollution control standards were met, but the one for nitrogen oxides was clearly in violation.

Shantanu Jathar is interviewed by CBS4’s Rick Sallinger (credit: CBS)

Sallinger asked Jathar, “In other words the car we drove flunked the test?”

He replied, “That’s true.”

The Volkswagen diesels are spewing as much as 40 times the allowed limit for those pollutants, according to the test results we and others performed.

(credit: CBS)

Dr. Anthony Marchese at the CSU engine lab believes the manufacturer will find a remedy.

“They are going to get to the bottom of it they might recall your vehicle,” Marchese said.

After we confirmed this particular Jetta diesel is in violation of EPA standards we took it to a testing station contracted by the state. But we learned the Colorado diesel emissions test checks for different pollutants. It simply looks at the density of the smoke which contains harmful particle pollution. The test is an indication of how clean the engine is running.

The Jetta being tested with State of Colorado testing equipment (credit: CBS)

The tester at Houska Automotive in Fort Collins informed us, “The engine light did not come on during the test. It blew very clean.”

And so $70 later the State of Colorado approved it.

The Jetta being tested with State of Colorado testing equipment (credit: CBS)

“I do. I feel like everybody else is playing by the same rules and they are trying to circumvent that,” he said.

The Jetta being tested with State of Colorado testing equipment (credit: CBS)

The pollutants VW hid create breathing problems, especially for the elderly. We found out the state does actually have a way to detect those pollutants. It’s a roadside test with boxes, but the vehicle owners are not being notified if there may be a problem. The state health department pointed out a roadside test is just a fraction of a second while the emissions test at stations are four minutes long.

What remains clear is that Volkswagen diesels are operating on Colorado roads in violation of the EPA standards.

And all this was happening while VW was selling cars billed as “clean” in advertisements and displays at dealers.

Jetta owner Chris Page isn’t pleased.

“I think they did mess up and they owe me the car that they said they were giving me,” he said.

The state health department says to change its testing and notification system would cost too much, adding the vehicles remain legal to drive while VW comes up with a recall plan.

CBS4’s Rick Sallinger is a Peabody award winning reporter who has been with the station more than two decades doing hard news and investigative reporting. Follow him on Twitter @ricksallinger.